add hard capacity ceiling to weight limit rules

apps/edr-freight-api/src/modules/train-scheduling/train-scheduling.service.ts

@@ -605,16 +605,22 @@ export class TrainSchedulingService {
     );
 
     if (!validation.valid) {
+      // Put the violation detail in the message itself — global exception
+      // filters flatten the body, and "Booking validation failed" alone tells
+      // staff nothing (e.g. which wagon type is missing at the yard).
       throw new BadRequestException({
-        message: 'Booking validation failed',
+        message: `Booking validation failed: ${validation.violations.join('; ')}`,
         violations: validation.violations,
         warnings: validation.warnings,
       });
     }
 
     if (!validation.bookings.length) {
+      const shortfall = validation.deferredBookings
+        .map((d) => `${d.reference}: ${d.reason}`)
+        .join('; ');
       throw new BadRequestException({
-        message: 'No bookings fit on available fleet wagons',
+        message: `No wagons available for the selected bookings${shortfall ? ` — ${shortfall}` : ''}`,
         violations: ['Insufficient fleet wagons for the selected bookings'],
         warnings: validation.warnings,
         deferredBookings: validation.deferredBookings,
@@ -628,12 +634,14 @@ export class TrainSchedulingService {
     if (!limitLoco) {
       throw new BadRequestException('Schedule train set has no locomotives');
     }
-    if (limitLoco.maxPullWeightTons < totalWeightTons) {
+    // forceAssign lets staff overload the locomotive set knowingly — the
+    // validator has already surfaced it as a warning in that case.
+    if (!dto.forceAssign && limitLoco.maxPullWeightTons < totalWeightTons) {
       throw new BadRequestException(
         `Train set locomotives cannot pull ${totalWeightTons}T`,
       );
     }
-    if (limitLoco.maxTrainLengthMeters < totalLengthMeters) {
+    if (!dto.forceAssign && limitLoco.maxTrainLengthMeters < totalLengthMeters) {
       throw new BadRequestException(
         `Train set locomotives cannot support ${totalLengthMeters}m`,
       );
@@ -2251,9 +2259,16 @@ export class TrainSchedulingService {
       max20ftPairWeightDiffTons: trainLimits.max20ftPairWeightDiffTons,
     };
 
+    // With forceAssign, capacity-shaped rules (train limits, total weight,
+    // locomotive capability) become warnings — staff owns the override. Physical
+    // impossibilities (no wagon of the required type at the yard, wrong route,
+    // wrong status) can never be forced and stay violations.
+    const pushLimit = (issues: string[]) =>
+      forceAssign ? warnings.push(...issues) : violations.push(...issues);
+
     if (resolvedMode === 'MIXED') {
-      violations.push(
-        ...validateMixedTrainLimits(wagonPlan, [containerWagonType, bulkWagonType], trainLimits),
+      pushLimit(
+        validateMixedTrainLimits(wagonPlan, [containerWagonType, bulkWagonType], trainLimits),
       );
       if (requireContainerPlacements) {
         const containerBookings = fittingBookings.filter((b) => b.freightType === 'CONTAINER');
@@ -2270,7 +2285,7 @@ export class TrainSchedulingService {
         );
       }
     } else {
-      violations.push(...validateTrainLimits(wagonPlan, wagonType, trainLimits));
+      pushLimit(validateTrainLimits(wagonPlan, wagonType, trainLimits));
 
       if (requireContainerPlacements && resolvedMode === 'CONTAINER') {
         violations.push(
@@ -2293,8 +2308,8 @@ export class TrainSchedulingService {
     );
     if (totalWeightTons > trainLimits.maxWeightTons) {
       const message = `Total booking weight ${totalWeightTons}T exceeds max train weight ${trainLimits.maxWeightTons}T`;
-      if (!violations.includes(message)) {
-        violations.push(message);
+      if (!violations.includes(message) && !warnings.includes(message)) {
+        pushLimit([message]);
       }
     }
 
@@ -2321,9 +2336,9 @@ export class TrainSchedulingService {
         (setLimits.maxPullWeightTons < totalWeightTons ||
           setLimits.maxTrainLengthMeters < totalLengthMeters)
       ) {
-        violations.push(
+        pushLimit([
           'Assigned locomotives cannot support the total train weight and length',
-        );
+        ]);
       }
     } else {
       const inServiceLocomotives = await this.locomotivesRepository.findAll({
@@ -2341,7 +2356,7 @@ export class TrainSchedulingService {
             Number(l.maxTrainLengthMeters) >= totalLengthMeters,
         )
       ) {
-        violations.push('No locomotive can support the total train weight and length');
+        pushLimit(['No locomotive can support the total train weight and length']);
       }
     }
 
@@ -3740,7 +3755,7 @@ export class TrainSchedulingService {
 
     if (!validation.valid) {
       throw new BadRequestException({
-        message: 'Booking validation failed',
+        message: `Booking validation failed: ${validation.violations.join('; ')}`,
         violations: validation.violations,
         warnings: validation.warnings,
       });

apps/edr-freight-api/src/modules/train-scheduling/wagon-plan.util.ts

@@ -210,7 +210,14 @@ export function expandBookingContainerUnits(bookings: Booking[]): ContainerUnitR
       const wagonsPerUnit = Number(line.containerType?.wagonsPerUnit ?? (sizeFt >= 40 ? 1 : 0.5));
       const perWagon = containersPerWagonFromType(wagonsPerUnit);
       const teuSlots = teuSlotsForSizeFt(sizeFt);
+      // The REAL per-container numbers/weights entered at booking time. Unit i of
+      // the line maps to units[i] (sortOrder order); the line-level number is only
+      // a legacy fallback — never invent numbers here.
+      const units = [...(line.units ?? [])].sort(
+        (a, b) => Number(a.sortOrder ?? 0) - Number(b.sortOrder ?? 0),
+      );
       for (let i = 0; i < qty; i += 1) {
+        const unit = units[i];
         rows.push({
           bookingId: booking.id,
           bookingReference: booking.reference,
@@ -219,12 +226,13 @@ export function expandBookingContainerUnits(bookings: Booking[]): ContainerUnitR
           containerTypeId: line.containerTypeId ?? '',
           containerTypeCode: code,
           label: `${booking.reference} · ${i + 1}/${qty} · ${code}`,
-          grossWeightTons: Number(line.vgmPerUnitTons),
+          grossWeightTons: Number(unit?.vgmTons ?? line.vgmPerUnitTons),
           sizeFt,
           wagonsPerUnit,
           containersPerWagon: perWagon,
           teuSlots,
-          containerNumber: line.containerNumber ?? null,
+          containerNumber:
+            unit?.containerNumber?.trim() || line.containerNumber || null,
         });
       }
     }